Hot gas engine heater head

Abstract

A heater head for a multi-cylinder double acting hot gas engine in which each cylinder is surrounded by an annular regenerator unit, and in which the tops of each cylinder and its surrounding regenerator are interconnected by a multiplicity of heater tubes. A manifold for the heater tubes has a centrally disposed duct connected to the top of the cylinder and surrounded by a wider duct connecting the other ends of the heater tubes with the regenerator unit.

I claim: 
     
       1. A hot gas engine heater head in which an oscillating flow of gaseous working medium is heated and circulated between a cylinder and a regenerator cavity surrounding said cylinder, said heater head comprising: a plurality of tubes, each being connected at one end to a first manifold providing entrance to said cylinder and at the other end to a second manifold providing entrance to said regenerator cavity;   said first manifold being connected to said cylinder top via a central duct;   said second manifold being connected with said regenerator cavity via a second duct surrounding said central duct and having an annular cross section.   
     
     
       2. A heater head according to claim 1, wherein said ducts are coaxially arranged relative to said cylinder. 
     
     
       3. A heater head according to claim 2, wherein said first and second manifolds are located substantially in planes perpendicular to the axis of the cylinder and at two different levels. 
     
     
       4. A heater head according to claim 1, wherein said cylinder includes a sleeve disposed concentrically within a regenerator housing and defining said regenerator cavity therebetween. 
     
     
       5. A heater head according to claim 4, wherein said first and second manifolds and said ducts are defined within a manifold housing, said manifold housing having a pair of concentric necks, one of which is connected in an opening in said regenerator housing, and the other of which is connected to an opening in said cylinder. 
     
     
       6. A heater head defined in claim 5, wherein said central duct is defined within said other neck, and said annular duct is defined between said necks. 
     
     
       7. A heater head for a hot gas engine, comprising: a cylinder containing a reciprocating piston;   a regenerator housing surrounding said cylinder and defining therebetween an annular regenerator cavity;   first means defining an opening in the top of said regenerator housing;   second means defining an opening in the top of said cylinder;   a unitary manifold housing having a first portion which engages said first means with a hermetic seal and a second portion which engages said second means with a tight seal;   a first manifold in said manifold housing communicating through a first duct with said regenerator cavity;   a second manifold in said manifold housing communicating through a second duct with said cylinder;   said second duct being concentrically disposed within said first duct.